1. Field of the Invention
The invention relates to a television camera comprisingg a solid-state pick-up device having pick-up elements arranged in rows and columns and control electrodes coupled thereto for obtaining a charge transfer between pick-up elements, and also a control circuit, coupled to the control electrodes the pick-up device producing an interlaced television picture signal by means of this control circuit and these control electrodes, with field periods forming a frame period, each field period comprising a field scanning and blanking period.
2. Description of the Prior Art
Such a television camera is described in an article in the periodical "IEEE Transactions on Electron Devices", Vol. ED-20, No. 6, June 1973, pages 535 to 541, inclusive. The article discusses the problem of how to cause a television camera comprising a solid-state pick-up device to produce a single, 2:1 interlaced picture signal. A solution described therein is to compose different combinations of pairs of the rows of opto-electronic pick-up elements in two field periods, which together form a frame period. Thus, the items of information obtained from the sequentially numbered rows 1,2,3,4,5,6 etc. of pick-up elements can be combined in the first field period to form information associated with odd television lines 1,3,5 etc. in accordance with the formula: rows 1+2, 3+4, 5+6 etc., and in the second field period combinations of information can be formed associated with even television lines 2,4,6 etc. in accordance with the formula: rows 2+3, 4+5, 6+7. In addition it is disclosed that when the solid-state pick-up device is a biphase-controlled charge transfer device, the pick-up devices each having two control electrodes, it is possible to apply to these control electrodes a voltage of such a value that a light integration and charge storage corresponding to optical information is effected in the first field period for one control electrode and for the other control electrode in the second field period. In these two described cases the center point of the light integration areas with the charge storage at the solid-state pick-up device are moved to a central position, which corresponds to an interlace on recording and display of the picture signal.
It is further described that when the solid state pick-up device is in the form of a three-phase-controlled charge transfer device, the storage elements each comprising three control electrodes, a shift of the center points of the light integration areas with the charge storage can be realized by biasing in the first field period one of the three control electrodes for the charge storage and biasing the other two control electrodes in the second field period. In this situation, the light integration areas with the storage of information active in the first field period are not the same shape as those active in the second field period, which may be considered as a drawback, as the shifted light integration area is then indeed of the same size, but the area for charge storage is approximately doubled. On display of the picture signal, this might result in luminance variations between the picture signal of the first and second field periods, which may result in annoying flicker phenomena occuring at the picture frequency.